Door sensors (sometimes known as photoelectric or infrared beam, electric safety door edges, door detector, electric proximity edges, or electric doorman) is an elevator device that detects a passenger or an object on the doorway which prevents the doors from closing (usually installed for accessibility). If a person or an object blocks the doorway and the sensors detects the person or object, the door will reopen then stays open and will not closed until the person moves away or the object is removed from the doorway. If the doors are being held open for a more than the specified period, the elevator will go into nudge mode and the doors will close slowly with a continuously beep. The door sensors will not work on the fire service mode, hence the fireman's elevator still need mechanical safety edges when the sensor not working.
In some door sensors (like Memco Panachrome), there are LED illumination lamps inside the sensors that indicate the door movement, usually green for door opening and flashing red for door closing. Some door sensors used in Otis, Schindler, and Kone emits a continuously beep when a person entering and exiting the elevator, and blocks the doorway (by sensor system setting).
Door sensors are also possible to detect an object or obstacle blocking the doorway.
Types of elevator door sensors
For all the elevators with the door sensors may need an independent power supply to make the sensors work. Door sensors are usually work with a pair, The transmitter unit (or TX unit) which present the infra-red beams to the receiver unit (or RX unit) to receive the infra-red beams and make the sensors working.
Normal door sensors
This type is just a normal door sensors installed inside the car doors, not on the inside of the outer landing doors.
Mixed door bumpers and sensors
- Main article: Door bumpers
These are mechanical door bumpers but with built-in door sensors. Some elevator manufacturers like Shanghai Mitsubishi, GoldStar and LG (both were in the 1990s), and others are using this type of door sensors.
Alternatively known as photo eyes, this type if sensor consists of two small infrared sensors or light bulbs (in older elevators) located on the knee level of the car door jambs. They can also be found on the hall door jambs but these are very rare.
Safety ray are one or two infrared-light beams that cover the full width of the doors.
Multi-beam door sensors
These are multiple infrared-light beams that covers some 1800mm in height of the doors.
3D multi-beam door sensors
These door sensors are similar to the multi-beam type mentioned above, but has 3D sensors that monitors the hall by expanding multiple infrared-light beams.
Ultrasonic door sensors
These are door sensors that uses sound waves to scan a 3D area near the open doors. This type is very rare found in most modern elevators.
Notable elevator door sensors manufacturers
- Main article: List of non-proprietary elevator component companies
- AA Electric
- Formula Systems (division of Airdri Group)
- Ningbo Safety Electronic Co. Ltd. (SFT)
- TL Jones
- Ningbo Weco Optoelectronic
- Wittur/Selcom (usually packaged with their door operator)
Notable elevator door sensors
- cegard/Max (CEDES - used for Schindler's Progard L equipment, discontinued)
- cegard/Mini (CEDES, also known as Progard L by Schindler America)
- MiniMax (CEDES)
- Formula VISION Series 1 and 2 (Formula Systems)
- LAMBDA (Otis)
- MANSAFE (Formula Systems - Witney Oxfordshire)
- MicroLight (Dover Elevators)
- Microscan (TL Jones - currently replaced to M-Series/M-Class)
- Panachrome 3D and C3540 (Memco)
- S100-R (Shanghai Mitsubishi)
- SFT-627/637 (SFT - for Toshiba elevators only)
- SafeScreen (Formula Systems)
- SafeZone 3D (Formula Systems - will be replaced by the new VISION series)
- SlimScreen (Formula Systems - current Kone elevator door sensor with AMD door operator and also known as SRC RNC)
- WSE-81 Plus and 151 Plus (Wittur - option for Kone elevator door sensor with AMD door operator)
- See also: Nudge mode
Standing in-between the door sensors for a pre-defined amount of time will trigger nudge mode in some elevators. The door will slowly close followed by continuous beep or buzzer.
Notes and references
- What is an elevator? (by Dover Corp.)
- 【TOSHIBA ELEVATOR】Functions：Door safety functions (English)
- Elevator Hall Button Repairs
- TX unit mounted on the other side of the doors.
- RX unit mounted on the other side of the doors.
- But elevators installed with Wittur door operator can be mounted with other sensors such as TL Jones or Weco.
- MicroLight Door Protection System (archived)
- KONE Elevator Glossary - SRC RNC curtain of light